title: Combined toxicity of pesticide mixtures on green algae and photobacteria.
abstract: Different organisms have diverse responses to the same chemicals or mixtures. In this paper, we selected the green algae Chlorella pyrenoidosa (C. pyrenoidosa) and photobacteria Vibrio qinghaiensis sp.-Q67 (V. qinghaiensis) as target organisms and determined the toxicities of six pesticides, including three herbicides (simetryn, bromacil and hexazinone), two fungicides (dodine and metalaxyl) and one insecticide (propoxur), and their mixtures by using the microplate toxicity analysis. The toxicities of three herbicides to C. pyrenoidosa are much higher than those to V. qinghaiensis, and the toxicities of metalaxyl and propoxur to V. qinghaiensis are higher than those to C. pyrenoidosa, while the toxicity of dodine to C. pyrenoidosa is similar to those to V. qinghaiensis. Using the concentration addition as an additive reference model, the binary pesticide mixtures exhibited different toxicity interactions, i.e., displayed antagonism to C. pyrenoidosa but synergism to V. qinghaiensis. However, the toxicities of the multi-component mixtures of more than two components are additive and can be predicted by the concentration addition model.
authors.affiliation: Key Laboratory of Yangtze River Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China. ssliuhl@263.net
authors.forename: Shu-Shen
authors.initials: SS
authors.lastname: Liu
authors.forename: Cheng-Lin
authors.initials: CL
authors.lastname: Wang
authors.forename: Jin
authors.initials: J
authors.lastname: Zhang
authors.forename: Xiang-Wei
authors.initials: XW
authors.lastname: Zhu
authors.forename: Wei-Ying
authors.initials: WY
authors.lastname: Li
mesh_terms: D000409:Alanine / Q000031:analogs & derivatives / Q000633:toxicity; D001976:Bromouracil / Q000031:analogs & derivatives / Q000633:toxicity; D002708:Chlorella / Q000187:drug effects*; D004347:Drug Interactions; D006146:Guanidines / Q000633:toxicity; D010575:Pesticides / Q000633:toxicity*; D010776:Photobacterium / Q000187:drug effects*; D001074:Propoxur / Q000633:toxicity; D014227:Triazines / Q000633:toxicity; D014733:Vibrio / Q000187:drug effects*
chemical_list: D006146:Guanidines; D010575:Pesticides; D014227:Triazines; C033807:simetryn; C028175:metalaxyl; C006921:dodine; D001976:Bromouracil; D001074:Propoxur; C004590:bromacil; D000409:Alanine; C025641:hexazinone
keywords: Antagonism; Chlorella pyrenoidosa; Concentration addition; Synergism; Vibrio qinghaiensis sp.-Q67